Light is one of several energies that influences the world. It is an almost gelatinous substance that softly glows white. It does not illuminate its surroundings, as its name would imply. It is the polar opposite of Chaos, and is made stable by Darkness. The substance is the structural basis for the Night.
Origins of Light
Light in its entirety comes from Oneiris. The World of Dream is deeply connected to Mundis, and Light freely flows between the two. The act of dreaming beckons Light into the world, and thus it naturally occurs in the world at greater levels during the night.
Effects on the Individual
Light has a tremendous calming effect. In small doses, it has been used - illegally - as a tranquilizer. Symptoms escalate to frequent and heavier sleep, frequent comatoes conditions, glazed eyes, and a soft glow to the skin. In rare cases, the individual may be completely devoured by the Light, and will become integrated with Oneiris. (see: Representatives) During Oneiric Sleep, the individual experiences incredibly vivid and lifelike dreams, which typically turn into Nightmares. A Nightmare (different from the improper noun, "nightmare") is a general term used to reference any individual devoured by Light or attacked by a Night.
Relationship with Chaos
As mentioned, Light is the polar opposite of Chaos. When the two meet, they eliminate each other (with disastrous side effects). If an individual infected with Light meets an individual infected with Chaos, the two will feel pain when their skin touches, and that pain escalates and becomes more easily triggered with higher levels of each respective substance. There have been cases in which an Oneiric Representative who was near-integration inadvertently destroyed another individual with small levels of Chaos inside him. The proximited triggered the energies actions, and the Chaos cells extinction inside the victim devoured his body.